At the university of Washington research is progressing in the brain to brain communications interface. I already posted news on their results and here is the most recent one.
They have succeeded in transmitting information from one brain to another via a communication link (internet) using a simple protocol of "Yes" or "No" signals.
The "sender" brain is in a person that is looking at an object and sees two LEDs, one green and one red. That person is asked a question by the receiver, like "does it fly?", via a text message and should look at the green LED to respond Yes, to the red one to respond No.
The electrical signals detected by sensors on his head can tell if the person has looked at the green or the red LED. This information is conveyed via Internet to a coil on the receiver skull. This lead the coil to emit an electromagnetic field that creates a phosphene (the perception of a blob of light in the visual cortex) and this is associated to the "yes" answer. In this way the receiving brain becomes aware of what the transmitting brain did.
It is a very coarse way of communications but, like in some of the plays we used to do as child, it allows communications.
Researchers are confident that progress will improve the effectiveness of communications and are seeing a not distant future where a brain can be tutored by a teacher allowing a transfer of knowledge (a dream of mine when I was a student...). And before that time they see the possibility to help children with ADHD -Attention Deficit Hyperactivity Disorder- by connecting their brain to a normal child brain so that they can be conditioned to "pay attention" when needed.
Intersting as well as scaring scenarios ahead of us...